Mechanical pencil



Dec. 26, 1939. L. J. Mos-r MECHANICAL PENCIL FiledSept. 30, 1959INVENTOR luif- Most. WM

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atented Elec, 2S, i939 STATES PATENT orrica 5 Claims.

My invention relates to mechanical pencils of the type in which the leadis an instrumentality of the pencil mechanism.

The object of the invention is to provide leads that will interlock inthe means for feeding the lead and thereby provide a continuity of feed.

In my allowed application Serial No. 279,072, iiled June 14, 1939,allowed July 21, 1939, I have disclosed a pencil with prismatic leadswhich is the shape most suitable for leads whose average diameter incross-sectional area is less than 115th of an inch. For leads having incross-section diameters larger than gth of an inch the shape may beeither cylindrical or oval, and therefore not necessarily prismatic, asthe guides in such larger diameters can be easily made to suit thecross-section of the larger diameter of either oval or circular shapedleads in cross-section.

In the appended drawing forming part or' this application, Figure 1 is afragmentary vertical section on line I-I, Figure 2, showing a pencilembodying my invention.

Figure 2 is an enlarged cross-section on line 2 2, Figure 1.

Figure 3 is an enlarged cross-section of a pencil having an oval shapedlead guide, and thereore, oval shaped lead in cross-section, and

Figure 4 is a perspective view of a lead oval in cross-section.

Referring to the drawing, 5 is a barrel which is provided with acustomary tip 5 terminating at the lead outlet with a threaded bore 7.Positioned within the barrel and revolving relatively thereto is amagazine 8 having a lead guide 9 of circular cross-section extendingthrough the bore lil of the tip and leading to the threaded bore l.

The magazine is provided with an outer bead Il bearing against a ring I2secured within the barrel, and with the bearing of the end of the leadguide 9 on the bottom of the bore I0, the

magazine is prevented from longitudinal dis.

placement in the barrel. The magazine carries an eraser I3 and a cap Idby which the magazine may be turned in the barrel. The leads I5 for thepencil in this particular case are cylin drical and are circular incross-section similar to the lead guide 9. To prevent the lead fromturning in the guide the lead is provided with a keyway I6 which isengaged by protuberances I1 formed in the guide preferably near the endsthereof.

Each of the leads has its ends cut on a bias, that is to say, formingslopes Ie which are at an angle with the axis of the lead. When a leadis fed through the threaded bore 'l of the tip by the turning of themagazine, the upper end of slope I8 of a lead I5 passes from themagazine into the guide 9 when another lead I5 will enter into the guide9 following the lead which is already in the guide. If the two slopes I8of the contacting leads do not meet properly at the time, they willtravel that Way toward the threaded bore l' until the lower lead I5passes substantially into the threaded bore 'l when it will remainstationary, while the lead above it will be turned by the guide 9 whichturns with the magazine. This brings the slope I8 thereof in registerwith the upper slope I8 of the lower lead I5 positioned in the threadedbore 'I of the tip, as shown in Figure 1. In consequence of thisengagement, the lower portion of the lead I5 will turn when the upperlead I5 above it is turned by the magazine through the guide 9. Thisengagement of the contacting slopes of the leads insures the expulsionof the lead section engaged in the threaded 20 bore l.

In Figure 3, the lead barrel 5f has the lead magazine 8 provided with alead guide 9' which is circular exteriorally but oval interiorally, thatis, the passage I0' of the lead guide is oval in 25 cross-section toengage a lead I5' of similar crosssection. In this arrangement nokeyways in the lead proper are necessary since the lead will not turn inthe lead guide, although it is free to move longitudinally due to itsshape.

Figure 4 illustrates in perspective a lead as shown in the cross-sectionof Figure 3.

In lieu of forming a. keyway, as shown in the leads of Figures 1 and 2,a flat surface in lieu thereof could be provided which will answer thesame purpose. It is self-evident that the lead guide will havecorresponding flat surfaces to engage the lead and prevent it. fromturning while permitting it to move longitudinally thereof.

The fact that the lower lead when entirely in the threaded bore 1remains stationary but the lead above it will turn until the two slopesmeet, does not necessitate an exact cutting of the slope or relativelyto the configuration of the lead used.

Although the description and drawing refer to a threaded tip mechanism,it is obvious that a threaded member for the lead may be located at anyother portion in the barrel or tip using the lead described, that is, alead having the ends cut on a bias.

I claim:

1. In a mechanical pencil, a. lead, means for feeding the lead, andmeans for preventing the lead from turning while permitting the lead tomove longitudinally thereof, said leads having its ends cut on a. bias.

2. A lead for a mechanical pencil having its ends cut on a bias.

3. In a mechanical pencil, a combination of a lead having its ends cuton a bias, and a guide for lead which permits said lead to movelongitudinally but prevents it from turning therein.

4. A lead for mechanical pencil having sloping ends.

5. A lead for mechanical pencil having sloping 5 ends lying insubstantially parallel planes.

LUCIFER J. MOST.

